/*
 * Copyright 2016 Miroslav Janíček
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.sandius.rembulan.util;

import java.util.NoSuchElementException;
import java.util.Objects;

/**
 * A byte iterator over byte arrays.
 */
public class ArrayByteIterator implements ByteIterator {

	private final byte[] bytes;
	private int idx;

	/**
	 * Constructs a new byte iterator of the array {@code bytes}.
	 *
	 * @param bytes  the byte iterator to iterate over, must not be {@code null}
	 *
	 * @throws NullPointerException  if {@code bytes} is {@code null}
	 */
	public ArrayByteIterator(byte[] bytes) {
		this.bytes = Objects.requireNonNull(bytes);
	}

	@Override
	public byte nextByte() {
		if (idx < bytes.length) {
			return bytes[idx++];
		}
		else {
			throw new NoSuchElementException();
		}
	}

	@Override
	public boolean hasNext() {
		return idx < bytes.length;
	}

	@Override
	public Byte next() {
		return Byte.valueOf(nextByte());
	}

	@Override
	public void remove() {
		throw new UnsupportedOperationException("read-only iterator");
	}

}
